Retain cycles in jdk based classes

I found retain cycles in JDK based java classes which cause memory leaks on iOS. Below are some snapshots from Instrument Leaks tool.

- [LinkedHashMap](https://docs.oracle.com/javase/8/docs/api/java/util/LinkedHashMap.html) retain cycle:


- [DateTimeFormatterBuilder](https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatterBuilder.html) retain cycle:


Similarly, there seems retain cycle in [AbstractMap](https://docs.oracle.com/javase/8/docs/api/java/util/AbstractMap.html). Because `AbstractMap` retains `values` and `values()` use anonymous inner class which has implicit reference back to `AbstractMap`.

Does j2objc takes care of memory leaks in JDK by patching them or any other way ?